Capstan construction for wire drawing machine



Feb. 13, 1968 R. 1.. FLESHMAN CAPSTAN CONSTRUCTION FOR WIRE DRAWING MACHINE 4 Sheets-Sheet 1 Filed Feb. 11, 1966 Feb. 13, 1968 R. FLESHMAN CAPSTAN CONSTRUCTION FOR WIRE DRAWING MACHINE 4 Sheets-Sheet 2 Filed Feb.

INVENTOR RICHARD L. FLESHMAN 5 9% Ana.

CAPSTAN CONSTRUCTION FOR WIRE DRAWING MACHINE LD //4 Q L31 V////4 v* m/ Q a, 5 INVENTOR RICHARD L.

FLESHMAN N 6 Wag L, 71144 4, 44.74 @W United States Patent 3,368,382 CAIS'IAN CONSTRUCTIGN FOR WIRE DRAWING MAtIHINE Richard L. Fieshman, Evergreen Park, Ill., assignor to Wire Machinery Inc, Chicago, Ill., a corporation of Iiiinois Fiieti Feb. 11, 1966, Ser. No. 526301 6 Ciaims. (Cl. 72-289) The present invention relates to wire drawing and more particularly to a capstan well suited to the drawing of wire in the larger gauges of special alloy or having a relatively high carbon content.

In the drawing of wire through a die to a predetermined diameter, either in a single pass or in multiple passes through successively smaller dies, the energy of the draw is released in the form of heat, increasing the temperature of the exiting wire. In heavy duty machines the temperature increase may be sufficiently great as to affect the hardness or other physical characteristics of the wire. Various schemes have been proposed to cool the wire; for example, it has been suggested that the capstan, or drawing block, be cooled by internal flow of cooling water. Unfortunately, providing for the flow of cooling water has, in prior constructions, required a sacrifice in strength, placing a limitation upon the size and carbon content of the wire as well as the speed of draw. Moreover, it has been necessary to resort to structures which are relatively complicated and difiicult to manufacture and maintain, for example, structures employing moving and stationary elements separated by large diameter seals. Also, prior capstans employing water cooling have been subject to deterioration in performance due to the insulating effect of rust or corrosion and deposits of lime or other foreign materials carried by the water.

It is an object of the present invention to provide an improved capstan construction of the water cooled type which not only establishes optimum cooling conditions but in which the cooling is accomplished without sacrifice of physical strength and without resort to a complex or expensive multi-part construction. Indeed, it is an object of the present invention to provide an improved capstan which has a high inherent strength, with each of the capstan sectors being box-like and monolithic having a strength equal to or exceeding that of ordinary uncooled capstans of approximately the same size. It is another object of the invention to provide a water-cooled capstan in which turbulent flow, with scrubbing of the water against the sides of the water chambers, is assured and in which such chambers are easily and quickly accessible for cleaning in order to remove rust or other deposits, without necessity for removing the capstan from the wire drawing machine.

In one of its aspects it is an object of the present invention to provide a water-cooled capstan having a novel arrangement for circulating the cooling water to the respective sectors, the water being fed and returned through passages provided in the central shaft upon which the capstan is mounted. In this connection it is an object of the invention to provide a structure which enables use of a simple swivel coupling for conducting the water and which does not require any dependence upon special large diameter seals.

It is a still further object to provide a capstan which may be used with or without a separate bottom block and in which the cooling system of the bottom block is readily integrated with the cooling system of the capstan.

Other objects and advantages of the invention will become apparent upon reading the attached detailed decription and upon reference to the drawings in which:

FIGURE 1 is a perspective view of a vertical bull block employing a capstan constructed in accordance with the present invention and with a wire stripper in place;

FIG. 2 is a partial plan view of a capstan constructed in accordance with the present invention, but with stripper and cover plates removed;

FIG. 3 is a transverse section of the capstan of FIG. 2 looking along the line 33 in FIG. 2;

FIG. 4 is a fragmentary section taken along the line 44 in FIG. 2 showing the construction of the bottom block;

FIG. 5 is a fragmentary section taken along line 55 in FIG. 2;

FIG. 6 is a fragmentary section taken along line 66 in FIG. 2.

FIG. 7 is a fragmentary section of the cooling fluid connection arrangement to the lower end of shaft 12.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to be limited to the embodiment shown but intend to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to the drawings, FIGURE 1 shows a wire drawing machine It) having a frame 11 in which is journaled a vertical drive shaft 12. carrying a capstan 13 for pulling a wire I4- through a reducing die 15. If desired an idler pulley 16 may be used to guide the wire from the die to the capstan. The shaft 12 is rotated by a motor 17 having a speed reducer (not shown) to produce high torque combined with the desired speed of draw, for example, between 50 and 3000 feet per minute depending upon torque available, size of wire, and other considerations. Briefly stated, the wire 14 which is pulled through the die is wrapped about the lower portion of the capstan, the lower convolution serving to constantly crowd the earlier convolutions upwardly into a loose coil 18 surrounding a set of accumulator pins 19. A conventional stripper of the rigid or collapsible type having vertical legs 21 terminating in outwardly projecting feet 22 and having a lifting eye 233, permits the completed coil to be easily stripped or removed from the capstan.

Turning next to the details of the capstan construction as shown in FIGS. 2 and 3, the. capstan includes a base portion 31 having an annular ramp 32 extending about its periphery and having a hub 33 at the center keyed to the shaft 12. At the inner edge of the ramp 32. is a corner 35 which receives the lead of wire, with an adjacent, generally cylindrical crowding surface 36 along which the earlier convolutions are laterally crowded. In a typical case the crowding surface 36 may have a draft on the order of 0.75 and the ramp 32 may have a ramp angle of approximately 8. The convolutions on the crowding surface provide suflicient purchase so that a force may be developed in the entering lead of wire, more than adequate to overcome the resistance of the die. At the upper edge of the surface 36 there is a region of drop-off 37 followed by a terminal portion 38 of reduced diameter. The convolutions of wire, while tightly wound on the initial,

or lower, portion of surface 36 are thus freed in loose condition at the region of drop-off. The oncoming convolutions serve to progressively build up the coil 18.

For the purpose of supporting the stripper, the capstan has a plurality of radial clearance slots or grooves 41 which merge with notches 42- formed in the ramp portion of the base. The grooves 41 accommodate the legs 21 of the stripper with the outwardly projecting feet 22 thereon lying within the respective notches 42 below the level of the ramp surface. Upon attaching the hook of a hoist to the eye at the top of the stripper, and upon severing the wire lead, the coil of wire on the capstan may be stripped off and a new coil started.

In accordance with the present invention a plurality of drawing sectors are provided as an integral part of the capstan, with each of the sectors having an outer segmental wall and an inner segmental wall spaced there from together with radial supporting walls which extend inwardly to the hub to define an arcuate interspace having substantial radial thickness and into which cooling liquid, preferably water, is forced under pressure for turbulent scrubbing of the cooled surfaces. Thus, referring to the drawings, a typical sector 50 has an outer segmental wall 51 and an inner segmental wall 52 which are joined at their ends by a first radial wall 53 and a second radial wall 54, the inner ends of both of the latter extending convergin-gly to the hub 33. The walls, taken together, define an arcuate cooling chamber 60 to which water is admitted, at one end, by an inlet connection 61 and discharged, at the opposite end, via an outlet connection 62. For completely enclosing the chamber 60, an arcuate cover plate 63 is provided having a gasket 64 and which is secured in place by means of bolts 65 threaded into tapped holes along the upper edges of the walls.

Cooling water is admitted into the inlet connection 61 with sufiicient pressure and at a sufficient rate of flow to produce turbulence as indicated diagrammatically in FIG. 2, with the water currents serving to scrub the inner surfaces of the walls 51, 52. In the practical case of a capstan intended for heavy duty usage, the cooling water may, for example, flow at the rate of l2 gallons per minute, sufficient for turbulent action. In accordance with one of the more detailed aspects of the present invention and to secure turbulence even at lower rates of flow, the chamber 60, between inlet 61 and outlet 62, may be necked down as indicated at 66 (see also FIG. 6), effectively dividing the chamber 60 into two interconnected chambers having a transition in which the velocity is increased. This insures turbulence adjacent the output as well as in the region where the turbulent inlet stream is received. In a practical case the restriction 66 may be formed by an embossment or enlargement 67 integrally formed on the outer wall and which provides reinforcement for a hole 63 in which an upwardly extending accumulator pin 19 is mounted.

In carrying out the invention the walls 51, 52 as well as the walls 53, 54 are of relatively massive cross-section so that the sector 50 taken as a whole, is box-like and monolithic, of great inherent strength and suited to the drawing of the heaviest commercial gauges of carbon steel wire. Preferably the grooves 41, which separate the adjacent radial walls, are of tapering depth as shown in FIG. 5, becoming shallower approaching the hub to provide a heavy cantilevered section. Thus, instead of the capstan being weakened by the grooves and cooling chambers, the capstan has a strength, for its intended purpose, which is equal to or better than capstans of conventional uncooled design of about the same size and weight. It will be noted in the drawings that each of the sectors includes a central access space 70 which provides space for the necessary fittings such as indicated at 71, 72. The outlet of one sector is connected to the inlet of the next by short lengths of hose diagrammatically indicated at 73.

In carrying out the invention the cooling water is led into and out of the cooling chambers via passages which extend axially within the drive shaft, and a swivel fluid connection is provided at the remote end of the drive shaft for connection to the source of cooling water and the drain or sump. Thus, referring to FIGS. 3 and 7, the shaft 12 has a central bore 80 which accommodates a pipe 81 defining an annular inlet passage 82 and a central drain passage 83. The latter are connected, via a T connection 84 and an elbow 85, to inlet and outlet hoses 86, 87 respectively. At the remote, or lower, end of the drive shaft, a swivel connection 0 is made up of a cylindrical housing 91 mounted on a quill shaft 92 with bearings 93 interposed between them. Leakage of fluid into the bearin gs is prevented by a seal 94, the sealing surfaces being kept in engagement by a spring 95. A conduit 96 provides communication between a source of cooling water 97 and the passage 82 in the shaft. A second 'conduit 98 serves to connect the central drain passageway to the drain or sump 99. It will be apparent that such arrangement utilizes sealing elements 94 of small diameter running less chance of leakage than the large diameter seals sometimes used and available at substantially reduced cost.

In accordance with one of the detailed aspects of the present invention, a bottom block of fiat cylindrical configuration is provided, secured to the underside of the capstan described above and which is keyed to the same drive shaft and which has novel provision for sharing the same cooling means. Such bottom block, indicated at 100 in FIG. 3, provides a second wire engaging surface of lesser diameter and is utilized where it is desired to ac complish two successive reductions with a single capstan assembly. In the present instance the wire engaging surface is made up of segmented slip shoes 101 arranged end to end and preferably five or more in number. When the increase in length of the wire resulting from the reduction of area at the second die is in the same ratio as the diameters of the capstan and lower block, slippage at the lower block is minimized. However, it is contemplated that where such slippage does occur in the lower block, either forwardly or reversely, such slippage should be accommodated by bodily movement of the shoes rather than by slippage of the wire itself. The lower edges of the shoes in the present construction ride against an annular main plate 102 which is secured to a hub 103 by a set of four radial members or spokes 104. For the purpose of providing a cylindrical supporting surface for the shoes having structural rigidity, and to provide circulation of cooling water to carry away the heat from the drawn wire, a pair of annular rim members 105, 106 are provided having an annular cover member 107 bolted in place to define a boxlike cross section having an annular cooling space 108.

To complete the construction of the bottom block and to provide a chamber for conducting of pressurized cooling air to the capstan, an annular plate 110 is provided. The inner portion of the plate is machined, as indicated, to fittingly receive the upper edges of the slip shoes and the upper surface of the annular member 107. The inner diameter, indicated at 112, is such as to provide a relatively large cross section for flow of air. With the outer edge or lip of the plate 110 engaging the underside of the ramp portion to provide an airtight joint, a volume of cooling air is conducted to openings 113 in the ramp.

In order to clamp the bottom block securely to the underside of the capstan, a pair of diametrically arranged risers are employed. One of these risers, indicated at (FIGS. 3 and 4), is welded to a rib 104 at its lower end and extends upwardly through a clearance opening 121 in the capstan. The upper end of the riser 120 is tapered to receive a bolt 122 having a washer 123. It will be apparent, then, that turning the bolt 122 serves to draw the assembly together in an axial direction. Such clamping, however, does not affect the slippage of the shoes which is determined, primarily, by tailoring the cross sectional dimensions of the base portion of each shoe.

For the purpose of conducting the compressed air into the bottom block, the annular bottom plate is spaced reasonably close to the top surface 125 of the frame. Moreover, closely spaced about the periphery of the bottom plate 102, and secured to the surface 125, is an annular vane 126 which not only functions as a labyrinth but also serves to direct any escaping air upwardly toward the capstan to contribute to cooling.

In carrying out the invention the same stream of cooling water is utilized for cooling the capstan and bottom block. Thus inlet and outlet lines 131, 132 are used having fittings 133, 134 which are screwed into threaded openings provided in the annular wall member 105. A barrier 135 (see FIG. 4) insures circulation about the periphery. To connect the lines 131, 132, the input line 86 is preferably split to provide connections 137, 138 shown dotted in FIG. 3. Thus the low temperature inlet water is conducted directly to the annular circulation chamber 108 which is directly behind the slip shoes for absorbing the energy of slippage and preliminarily cooling the wire prior to passage of the wire through the second die indicated diagrammatically at 139. The necessary reversal of wire direction may be achieved by a suitable pulley 140. Where the inlet water has a temperature on the order of 65 F. and where the flow is adjusted to give an outlet temperature on the order of l0Ol2 0 F., the temperature of the wire as it leaves the capstan is sufficiently low so that the wire may be fed directly to the next drawing step, if desired, rather than being stored on the machine in the form of the coil 18.

Practical experience shows that the above described capstan assembly possesses a number of features and advantages to a useful degree. Not only is the structure of high inherent strength permitting the drawing of large gauge steel wire having a relatively high carbon content but the heat generated by the drawing process is efliciently dissipated. The machine may be operated continuously on a heavy-duty basis without requiring maintenance, and, when it is necessary to remove rust or sedimentation affecting the eflicient transfer of heat through the outer wall 51, this can be easily accomplished simply by removing the cover plates 63 and entering a sand blast nozzle, or other suitable cleaning tool, downwardly into the chamber 60. Such cleaning requires only a few minutes time and can be taken care of without removing the capstan from the machine.

While the capstan and bottom block construction, taken together, provide a compact construction which is thermally and mechanically integrated, it will be apparent to one skilled in the art that the capstan will, in most cases, be employed without the bottom block. Disassembly is easily achieved by loosening the bolts 122 and by restoring the fluid supply line 86, permitting the bottom block to be telescoped from the drive shaft. Its place on the shaft may be taken by a suitable spacer, or the capstan may be lowered in its position on the shaft so that the outer edge lies adjacent the top surface 125 of the frame. Moreover, in the following claims the term for use with a stripper simply indicates the normal mode of use, and it will be apparent that the capstan is of general application and may be used without a stripper if desired.

I claim as my invention:

1. In a Wire drawing machine for use with a stripper and having a power-rotated shaft and a source of cooling liquid, a capstan comprising, in combination, a circular base portion having an annular ramp extending about its periphery and having a hub at its center, a plurality of drawing sectors interposed between the hub and the ramp and together defining an outer generally cylindrical crowding surface, each of said drawing sectors having an outer segmental wall and an inner segmental wall spaced therefrom with the upper edges of the walls in alignment, each of said sectors further having radial walls joined integrally to the ends of the segmental walls and extending inwardly to the hub to define, with the segmental walls, a cooling chamber of arcuate section, arcuate cover plates on the upper edges of said walls to enclose the arcuate chambers, said radial walls defining radial grooves merging with notches in the ramp for seating therein the legs of the stripper structure, each of said chambers having wa er i e a d u e fittings, d d t me ns for 991 necting the fittings together and to the source of cooling liquid, all of said walls being of thick section so that each drawing sector forms a separate monolith, said segmental Walls being substantially spaced from one another to provide relatively large and accessible chambers for turbulent flow for cooling of said crowding surface and the wire which is progressively wound thereon.

2. The subject matter as claimed in claim 1 in which the inlet and outlet connections for each cooling chamber are arranged at the ends thereof and in which the central portion of each chamber has a portion of reduced cross section for insuring turbulent flow throughout the chambers.

3. In a wire drawing machine having a driving means and a source of cooling liquid, a capstan comprising, in combination, a circular base portion having an annular ramp extending about its periphery and having a hub at its center, a drive shaft in the hub connected to the driving means, a plurality of drawing sectors interposed between the hub and the ramp and together defining an outer generally cylindrical crowding surface, each of said sectors having an arcuate cooling chamber parallel with the crowding surface and thermally coupled to it, said sectors having cover plates to enclose the cooling chambers and having inlet and outlet passageways extending axially therein, conduit means for connecting the fittings and the passageways for flow of liquid therethrough, and a swivel connection having stationary inlet and outlet ports communicating with the passageways and adapted for connection to the source of cooling liquid as the capstan is rotated by the driving means.

4. In a wire drawing machine having a power rotated shaft and a source of cooling liquid and for use with a stripper, a capstan assembly comprising, in combination, a capstan having an annular ramp extending about its periphery and having a hub at its center, a plurality of drawing sectors interposed between the hub and the ramp and together defining an outer cylindrical crowding surface, each of said drawing sectors providing an arcuate chamber for cooling liquid thermally coupled to the adjacent portion of the crowding surface, said drawing sectors being spaced to define radial grooves between them merging with notches in the ramp for seating the stripper, each of said chambers having inlet and outlet fittings connected to the source of cooling liquid, and a lower block of fiat cylindrical shape secured to the underside thereof, said lower block having a winding surface thereon formed of a plurality of segmented shoes and means connected to the source of cooling liquid for cooling the shoes.

5. The subject matter as claimed in claim 4 in which an annular supporting member is provided for mounting the shoes for relative slipping movement and in which such supporting member has formed therein an annular cooling chamber for flow of cooling liquid.

6. The subject matter as claimed in claim 4 in which the ramp has air passages formed therein and in which the lower block includes an annular supporting member for supporting the shoes as well as an annular plate for engaging and enclosing the underside of the capstan, a source of cooling air, said plate having a central access opening for conducting the cooling air past the annular supporting member for cooling the same followed by flow of the air through the passages formed in the ramp.

No references cited.

RICHARD J. HERBST, Primary Examiner. H. DIE'ITER OINKES, Assistant Exgminer, 

1. IN A WIRE DRAWING MACHINE FOR USE WITH A STRIPPER AND HAVING A POWER-ROTATED SHAFT AND A SOURCE OF COOLING LIQUID, A CAPSTAN COMPRISING, IN COMBINATION, A CIRCULAR BASE PORTION HAVING AN ANNULAR RAMP EXTENDING ABOUT ITS PERIPHERY AND HAVING A HUB AT ITS CENTER, A PLURALITY OF DRAWING SECTORS INTERPOSED BETWEEN THE HUB AND THE RAMP AND TOGETHER DEFINING AN OUTER GENERALLY CYLINDRICAL CROWDING SURFACE, EACH OF SAID DRAWING SECTORS HAVING AN OUTER SEGMENTAL WALL AND AN INNER SEGMENTAL WALL SPACED THEREFROM WITH THE UPPER EDGES OF THE WALLS IN ALIGNMENT, EACH OF SAID SECTORS FURTHER HAVING RADIAL WALLS JOINED INTEGRALLY TO THE ENDS OF THE SEGMENTAL WALLS AND EXTENDING INWARDLY TO THE HUB TO DEFINE, WITH THE SEGMENTAL WALLS, A COOLING CHAMBER OF ARCUATE SECTION, ARCUATE COVER PLATES ON THE UPPER EDGES OF SAID WALLS TO ENCLOSE THE ARCUATE CHAMBERS, SAID RADIAL WALLS DEFINING RADIAL GROOVES MERGING WITH NOTCHES IN THE RAMP FOR SEATING THEREIN THE LEGS OF THE STRIPPER STRUCTURE, EACH OF SAID CHAMBERS HAVING WATER INLET AND OUTLET FITTINGS, AND CONDUIT MEANS FOR CONNECTING THE FITTINGS TOGETHER AND TO THE SOURCE OF COOLING LIQUID, ALL OF SAID WALLS BEING OF THICK SECTION SO THAT EACH DRAWING SECTOR FORMS A SEPARATE MONOLITH, SAID SEGMENTAL WALLS BEING SUBSTANTIALLY SPACED FROM ONE ANOTHER TO PROVIDE RELATIVELY LARGE AND ACCESSIBLE CHAMBERS FOR TURBULENT FLOW FOR COOLING OF SAID CROWDING SURFACE AND THE WIRE WHICH IS PROGRESSIVELY WOUND THEREON. 